Abstract

As an extension of the pure component property estimation techniques that we have developed for normal boiling points, critical property data, vapor pressures, viscosities and surface tension, a new group contribution method for the prediction of pure component saturated liquid thermal conductivity has been developed. Predictions can be made from simply having knowledge of the molecular structure of the compound. Structural group definitions for the method are a modified version of those proposed by Moller et al. for the estimation of saturated vapor pressures. Structural groups were defined in a standardized form and fragmentation of the molecular structures was performed by an automatic procedure to eliminate any arbitrary assumptions. The new method is based on liquid thermal conductivity data for about 330components after critical evaluation of 110,000 data points for the various phases and nearly 900 components stored in the Dortmund Data Bank. Results of the new method are compared to several other estimation methods published in literature and are found to be significantly better. A relative mean deviation in thermal conductivity of 3.87% was observed for a common set of 331 components (6264 data points). By comparison, the Nagvekar and Daubert method, the best literature method in our comparison produced a relative mean deviation of 7.03% for 206 components.

A group contribution method for the estimation of saturated liquid thermal conductivity was developed by Onellan Govender in his MSc. thesis (UKZN, Durban, ZA). It is available in the program package ARTIST by DDBST (www.ddbst.com).